等同原则是为了解决一种产品或方法没有正好落入某专利要求的字面范围内,但等同于权利所保护的发明时,传统理论无法保护专利权人的发明的问题。等同原则的适用应综合主观标准和客观标准,同时应受到禁止反悔原则和自由公知技术抗辩原则的限制。 The principle of equivalence is to solve the problem that a product or method does not exactly fall within the literal scope of a patent claim, but the traditional theory can not protect the invention of the patentee when it equals the invention protected by the right. The application of the principle of equivalence should be based on a combination of subjective and objective criteria, subject to the principle of the prohibition of repentance and the principle of free and well-known technology defense.